Solid-gelled oil composition and process of preparing same



Patented June 7, 1938 uNrrEo STATES SOLID-GELLED OIL COMPOSITION AND PROCESSOF PREPARING SAME Edward F. Arnold, Metuchen, N. J., and Michael J. Callahan, Wilmington,

Del., assignors to E. I. du Pont de Ncmours & Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application January 31, 1936, Serial No. 61,746

9 Claims.

This invention relates to new compositions including a solid-gelled oil and the method of preparing such compositions, and more particularly to cellulose derivative compositions including a solid-gelled oil, and is a continuation of our copending application Serial No. 545,840.

Heretofore cellulose derivative compositions, including difi'erent plasticizers, have been known. Various vegetable oils, both raw and blown, have been used for this purpose, castor oil being a particularly common plasticizer. Such compositions, although satisfactory for many purposes, are still open for improvement. Films made therefrom lose their flexibility and check in time. Another objection is that in coating porous surfaces, such as leather, particularly the deeper cuts, as splits and machine and deep buffs, these compositions have a tendency to strike in and do not have the desired leveling and filling properties. The use of linseed oil and other oxidizing oils in such compositions is objectionable due to the necessity of giving the coated product a baking treatment to promote oxidation of the oil to render the film,

tack free.

An object of the present invention is to provide a composition which gives a tack free, waterproof, elastic, flexible film of good adhesion. Another object is to provide a composition having filling and leveling qualities when applied to leather and similar porous surfaces. A further object is to provide a composition which will give a tack free film without baking and moreover is applicab e by dipping, brushing, spraying, or other methods of coating. A broader object of the present invention is to provide a composition adapted to be combined with cellulose derivatives or other film forming ingredients to provide compositions of advantageous properties. Otherobjects of the invention will be apparent from the description of the invention given hereinafter.

These objects are accomplished according to the present invention by the use of a solid-gelled non-drying vegetable oil.

By the term solid-gelled non-drying vegetable The solid-gelled non-drying oils are substantially oil is meant any vegetable oil that is not classified.

insoluble in the usual solvents and diluents used in various plastic and coating compositions and, in that respect, are sharply distinguished from the common solid plasticizers such as triphenyl phosphate, phenyl salicylate, and the like, used in cellulose derivative compositions and which are soluble in the usual solvents and diluents used in such compositions. It is because of their insolubility that the solid-gelled non-drying vegetable oils do not strike into porous surfaces, such as leather, but remain on the surface and have the desired leveling effect. By the term substantially insoluble used with respect to the solid-gelled oil is not meant absolute insolubility, as a small proportion of the solid-gelled oil will dissolve in alcohol. The soluble part may run as high as 5% of the total weight of the oil, at moderate temperatures, in various lacquer solvents and diluents.

Solid-gelled olls cannot be satisfactorily d spersed in a liquid medium by means of the ordinary mixing apparatus or by grinding in a ball mill. Due to the insolubility of the solid-gelled oil it does not get broken up and properly dispersed in a-liquid medium. It has been discovered that solid-gelled non-drying vegetable oils can be dispersed in a liquid medium in a fine state of division to give a substantially clear, homogeneous composition by first working the solidgelled oil on the ordinary roller mill until the oil changes from a substantially clear, translucent, almost transparent, mass to an opaque mass of decidedly yellow color and then dispersing the treated mass in a liquid medium by means of the ordinary mixer, or a ball mill, or other well known means. As far as is known. the resulting substantially clear, homogeneous composition, comprising solid-gelled non-drying vegetable oil dispersed in a liquid medium, is new With this composition any desired additional ingredient, such as gums, to give a varnish composition, or cellulose derivatives to give lacquer or plastic compositions, together with appropriate solvents and diluents for said gums or cellulose derivatives, may be incorporated in the usual mixer. Obviously, pigments may also be incorporated in these compositions by known mixing methods.

A preferred composition of the present invention comprises a cellulose derivative and a solidgelled non-drying vegetable oil. It has been found preferable in preparing such compositions to disperse the cellulose derivative in the solid-gelled oil, after said oil has been worked on the roller mill to a point where it becomes an opaque mass,

by feeding the cellulose derivative on to the roller. mill and continuing the operation until a homo geneous dispersion has been obtained and then incorporating the other ingredients to be-included in the composition in the usual mixer.- .If desired,

the cellulose derivative may be added after the.

- solid-gelled oil has. been dispersed in a liquid medium, such as a suitable solvent mixture'for the cellulosederivative, but this procedure is not preferred.

The exact'procedure to be followed may be varied, considerably and the following example is I iven to illustrate a preferred method of 'dis-.

persing nitrocellulose in solid-gelled castoroil. Example 1 Solid-gelled castor oil is fed on to a roller mill and the mass milled until the original structure of the oil is broken down and a yellow, opaque mass is obtained as contrasted with the clear," translucent, almost transparent, gelled oil before the treatment. This treatment causes no significant change in the actual consistency of the oil, although'aivery slight drop in consistency maybe observed if critically examined and the oil appears to be slightly more tacky. However, with the exception of the color and opacity changes -just noted, and the physical change I which is not visually apparent, but which nevertheless does take place since the oil may now be readily dispersed inan organic liquid medium, the oil in' other'respectsis in nature quite similar to the oil prior to the kneading treatment which is described in detail above. Nitrocottomeither dry or wetYwith alcohol, in the ratio of four parts of gelled oil toone'part of nitrocotton is added gradually with continued milling. The

milling operation is continued until the nitrocotton is uniformly dispersed throughout the oil medium. Pigments may be added at this point and the milling operation continued until they are uniformly dispersed. If desired, the pigment may be addedat an earlier stage in the milling. The resulting mixture is then removed from the roller mill and transferred to an ordinarymixer where suitable solvents and additional ingredients', suchlas plasticizers, resins, et'oetera, are added and the whole thoroughly mixed until a homogeneous mixture is obtained.

The following examples 'represent preferred To these compositions may be addedvarious piasticizing agents to further increase the 3111- ability and flexibility of fllms made therefrom.

9,120,088 Such plasticizers include tricresyl phosphate, di-

butyl phthalate, or various vegetable oils, such as castor, rape, cottonseed, perilla, linseed, and China-wood oils, either in the raw or blown state,;or mixtures of these plasticizers, such as Blendoyl, which consists of a combination of blown castor oil and blown rape-seed 011.,

While it is preferred to use cellulose derivatives in conjunction with the solid-gellednon drying vegetable oil, the present invention is by no means limited to that specific combination and includes within its scope the novel, substantially clear, homogeneous composition comprising solidgelled non-drying vegetable oil dispersed in a liquid medium, per se, or any other ingredients therewith. to give plastic or coating compositions.

' 'For example, the solid-gelled non-drying vegetable 011 may be dispersed in mineral spirits where itis to be used in a varnish composition, or in tobe m'ade.

Solid-gelled castor oil isthe preferred nondrying vegetable oil, but solid-gelled rape, cocoanut, and cottonseed oil, among others, are all useful in the present invention. It has been toluol where a cellulose derivative composition is found that these solid-gelled non-drying vegetable oils are substantially chemically inert at ordinary temperatures, and hence impart a long lasting flexibility to films, whereas films made from compositions including oils that gradually oxidize, such as linseed oil, become brittle and 4 crack under normal flexing. Due to. the solidgelled state of theoil-and its substantial insoluzbility in the ordinary solvents and diluents used' in coating compositions, the oil remains on the surface of leather splits and other porous surfaces, giving the compositions according to the p present invention filling and. leveling properties heretofore unequaled.

It is preferred to use cellulose nitrate as-the cellulose derivative, but other derivatives, such as ethyl cellulose andother ethers, cellulose laurate, cellulose nitrolaurate and other esters, may be used in place of cellulose nitrate. Furthermore, instead ,of a cellulose derivative, other film forming materials may be used, such as gums, to give a .varnish rather than a'lacquer.

It will be understood that the solvents and dil-.

uents given in the above examples can be replaced by other solvents and'diluents, such as are well known in the art, and that the proportions of ingredientsv can be'varied widely, for example, .the solvent and diluent content may be reduced to such; an extent .that a plastic composition is obtained rather than a liquid coating compositionllhe particular proportion ofingradients will be largely influenced by the use for which. the composition is desired.

Various resins, gums, pigments, or dyes may 5 be included in the compositions of the present invention. 1 v

' Among the advantages of the compositions according to the present invention are that compositions are provided which give a tack free coating without'the necessity of baking, and give films .of remarkable elasticity, flexibility, and filling and leveling qualities. These compositions have excellent adhesion and retaintheir flexibility and elasticity over remarkably long periods of time. These compositions'may' be applied by dipping, brushing, spraying, or any other known method of applying coating compositions.

These compositions are especially, advantageous for coating the deeper cuts of leather and similar porous surfaces because the solid-gelled oil is neither fugitive, nor does it strike in, and

consequently gives these compositions leveling and filling qualities never before attained. This property is attributable to the fact that the solidgelled oils are both solid and insoluble in the solvents and diluents used in the compositions.

We are aware that it has been proposed in Patent Nos. 1,794,325, 1,796,219 and 1,889,702 to treat certain oils in the presence of a catalyst with heat and air until they are oxidized to a crumbly mass, which are comparatively easily dissolved in ordinary cellulose nitrate solvents. We make no claim to the invention disclosed in those patents, since our process is concerned with the use of an oil which has not been oxidized and polymerized to a crumbly state and which likewise does not reach such condition by applying the very moderate milling treatment on the roller mill hereinbefore described.

As many apparent and widely difi'erent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments thereof except as defined in the appended claims.

We claim:

1. A substantially clear, homogeneous composition comprising a semi-plastic solid-gelled nondrying vegetable oil dispersed in a liquid medium, said oil having been rendered solid-gelled by treating it until semi-plastic, and stopping the treatment before the oil reaches the crumbly stage.

2. A substantially clear, homogeneous composition comprising semi-plastic solid-gelled castor oil dispersed in a liquid medium, said oil having been rendered solid-gelled by treating it until semi-plastic, and stopping'the treatment before the oil reaches the crumbly stage.

3. A coating composition comprising a homogeneous dispersion of cellulose nitrate, a solvent mixture including ethyl alcohol and ethyl acetate, a diluent and a semi-plastic solid-gelled non-drying vegetable 011, said oil having been rendered solid-gelled by treating it until semiplastic, and stopping the treatment before the oil reaches the crumbly stage.

4. A coating composition comprising cellulose nitrate, a semi-plastic solid-gelled non-drying vegetable oil, and a plasticizer, said oil having been rendered solid-gelled by treating it until semi-plastic, and stopping the treatment before the oil reaches the crumbly stage. I

b. A coating composition comprising cellulose 1 nitrate, a semi-plastic solid-gelled non-drying vegetable oil, and coloring matter, said oil having been rendered solid-gelled by treating it until semi-plastic, and stopping the treatment before the oil reaches the crumbly stage.

6. Process comprising working a solid-gelled non-drying vegetable oil on a roller mill until it is changed from a. translucent mass to a yellow opaque semi-plastic mass, without substantial change in consistency, and then dispersing same in a liquid medium, said oil having been rendered formly distributed in the solid-gelled oil, and then dispersing the mixture in a liquid medium, said oil having been rendered solid-gelled-by treat ing it until semi-plastic, and stopping the treatment before the oil reachesthe crumbly stage.

8. Process comprising treating semi-plastic solid-gelled non-drying castor oil on a roller mill until it changes from a translucent mass to a yellow opaque semi-plastic mass, without substantial change in consistency, feeding cellulose nitrate on to the roller mill and continuing the operation until the cellulose nitrate is uniformly distributed in the solid gelled castor oil, and then dispersing the mixture in a liquid solvent medium for the cellulose nitrate, said oii having been rendered solid-gelled by treating it until semi-plastic, and stopping the treatment before the oil reaches the crumbly stage.

9. A composition comprising a cellulose derivative and a solid-gelled non-drying vegetable oil, said oil having been rendered solid-gelled by 'treating it until semi-plastic, and stoppingthe treatment before the oil reaches the crumbly stage.

EDWARD I". ARNOLD. MICHAEL J. CALLAEAN. 

